Q. Back fill behind the abutments of bridges?
Dry Rubble - At the bank of all bridge abutments and wing walls, the space next to the masonry is to be filled in by a hand-packed dry rubble backing, to the thickness shown on the plans, or as directed by the Engineer.
Filling- Behind this dry rubble, the space upto the back of the excavation is to be filled with moorum, good granular yellow soil or other sound granular materials. Under no circumstances is black cotton or any clayey or silty soil to be used. This filling will be water and rammed in layer thickness. Each layer should have a slope of 45 o towards ground level, the slope to commence from immediately behind the abutment.